A — 1: μέσος
(Strong's #3319 — Adjective — mesos — mes'-os )

an adjective denoting "middle, in the middle or midst," is used in the following, in which the English requires a phrase, and the adjectival rendering must be avoided: Luke 22:55 , "Peter sat in the midst of them," lit., "a middle one of (them):" Luke 23:45 , of the rending of the veil "in the midst;" here the adjective idiomatically belongs to the verb "was rent," and is not to be taken literally, as if it meant "the middle veil;" John 1:26 , "in the midst of you (standeth One)," RV (lit., "a middle One"); Acts 1:18 , where the necessity of avoiding the lit. rendering is obvious. Cp. the phrases "at midday," "at midnight" (see MIDDAY , MIDNIGHT , above). Notes: (1) Mesos is used adverbially, in prepositional phrases, (a) ana m., e.g., 1—Corinthians 6:5 , "between;" Matthew 13:25 , "among;" Revelation 7:17 , "in the midst;" (b) dia m., e.g., Luke 4:30; 17:11 , "through the midst;" (c) en m., Luke 10:3 , RV, "in the midst," AV, "among;" so Luke 22:27; 1—Thessalonians 2:7; with the article after en, e.g., Matthew 14:6 , RV, "in the midst," AV, "before;" (d) eis m., Mark 14:60 , "in the midst;" with the article, e.g., Mark 3:3 , "forth" (lit., "into the midst"); (e) ek m., "out of the way," lit., "out of the midst," Colossians 2:14; 2—Thessalonians 2:7 , where, however, removal is not necessarily in view; there is no accompanying verb signifying removal, as in each of the other occurrences of the phrases; with the article, e.g., 1—Corinthians 5:2; 2—Corinthians 6:17; see WAY; (f) kata m., Acts 27:27 , "about mid(night)."

Matthew 14:24Philippians 2:15 Revelation 8:13HEAVEN
B — 1: μεσόω
(Strong's #3322 — Verb — mesoo — mes-o'-o )

"to be in the middle," is used of time in John 7:14 , translated "when it was ... the midst (of the feast)," lit., "(the feast) being in the middle."